Properties and Benefits of Soy: Glycine max, better known as soy beans or soyabeans, is a famous member of the legume family. This legume is now being cultivated throughout the world and marketed as a miracle functional food, wonder-meat replacement, saviour-staple food and cure-all vegetable. Soy is currently the number one substitute for meat and cost-reducing staple, present everywhere from baby formula and dairy to cold meats and sweets.
However, recent research has raised some serious questions regarding the safety of soybeans and soy products such as tofu, soy milk, soy yogurt, soy cheese, tempeh, soybean paste, soybean sprouts, soybean oil, soy sauce, soya chunks, soy meat used to make vegetable burgers and so on. Observational studies show that soybeans account for a great number of health problems both in several specific categories and in the general population.
What does the soybean plant look like? Soy is a general term given to soybeans, a vegetable in the legume family, related to beans, peas, chickpeas, lentils, peanuts, alfalfa and so on. Soybeans can grow in almost any type of soil and climate and vary considerably in appearance to the untrained eye. Plants range in height from 15-20 cm to almost 2 meters. Plants have small green leaves with 3 or 4 leaflets and small clusters of 5-8 cm long, green pod-like fruit containing the seeds we know as soya beans. The stem, pods and leaves of the plant are covered with a heavy coat of very thin gray hairs. When ripe, the pods turn brown.
There are different varieties of soy which explains why the hulls of the beans range in color from green, yellow and brown to blue, black and mottled, similar to beans. To give you a general idea, the soybean plant looks a lot like a small bean stalk with rich green foliage, the soybean pods resemble pea pods, while the soy beans themselves look a lot like beans.
What do soybeans taste like? Soybeans taste differently depending on how they are used. Edamame, which refers to raw, green (immature) soy beans in pods, is a popular traditional Asian soybean dish. The raw beans are usually either boiled or steamed and seasoned with salt or garlic.
Edamame has a sweet, slightly grassy taste. The reason why I am describing the taste of edamame as an already cooked dish is because raw, uncooked soybeans are toxic. Uncooked soybeans contain trypsin inhibitors, compounds that inhibit an enzyme that helps us digest proteins, potentially resulting in pronounced nutritional deficiencies and digestive problems. As for mature soybeans, taste perception and personal preferences play a crucial part in determining taste. While some people find them slightly sweet, with an almost imperceptible nutty flavor, others say they are flavorless or that they taste like cardboard.
What does soy milk taste like? Soy milk tastes a lot like skim milk to some, bean milk to others, while many appreciate its more creamy texture and light taste. What does tofu taste like? Tofu (bean curd) generally has a smooth, slightly soft texture, similar to that of a firm yogurt. Because it doesn’t really have any flavor, it takes on the flavor of the foods or sauces you serve it with.
From a nutritional point of view soy beans are a great food, rich in proteins (36.49 g of protein/100 g of soy beans, according to the USDA’s National Nutrient Database), dietary fiber (9.3 g), vitamins and minerals. In addition to this, soy beans were found to contain natural polyphenols claiming to restore hormonal balance, relieve hot flashes, reduce osteoporosis risks, lower cholesterol levels, provide antioxidant protection as well as exhibit a strong antiangiogenic effect as a result of which the legume is believed to contribute to the treatment of chronic diseases advancing by means of blood vessels proliferation (such as different types of cancer).
At the same time, thyroid problems, increased cancer risks and hormonal imbalances are just a few of the health risks we might be exposing ourselves to with a diet rich in soy products. But that’s a discussion for another day. According to research, here are 7 of the most noteworthy nutrition facts and health benefits of soybeans:
1) Rich source of protein. According to the USDA’s National Nutrient Database for Standard Reference, 100 g of mature, raw soybeans contains about 36.49 g of high-quality protein. More important, soy protein was found to contain all 9 essential amino acids the human body cannot synthesize, but requires to perform essential tasks such as synthesizing proteins and producing energy. While soy protein may not be as good as animal protein, studies confirm that soybeans is an ideal source of protein for anyone living a vegetarian or vegan lifestyle (learn more about the Health Benefits of Protein).
2) Help lower cholesterol. According to research, soybeans consumption is beneficial for cardiovascular health because the legume contains isoflavones, a sort of plant compounds that imitate the hormone estrogen. These isoflavones apparently bind to the surface of soy proteins, allowing for a decrease in both LDL (bad) cholesterol and triglyceride levels. (Meta-Analysis of the Effects of Soy Protein Intake on Serum Lipids, published in the New England Journal of Medicine, volume 2, no. 5, 1995). However, consuming soybeans and soy products does not increase HDL (good) cholesterol levels, most likely because of the estimated Omega-3-Omega-6 ratio of 1:7.
But at the same time, soybeans and soybean oil are a great source of alpha-linoleic acid, a plant form of Omega-3 (ALA). This polyunsaturated fatty acid is also found in walnuts, flaxseed, chia seeds and vegetable oils in general (see Nuts and Seeds Map). Healthy unsaturated fatty acids such as ALA help maintain artery health and clear cholesterol deposits that may affect the flexibility of blood vessels and limit blood flow, resulting in vascular problems such as atherosclerosis, a condition preceding cardiovascular disease. While eating healthy, plant-based fats is important for cardiovascular health, it does not make a great difference for individuals with a diet already rich in animal fat.
3) Excellent source of dietary fiber. Soybeans contain 9.3 g of dietary fiber/100 g. Dietary fiber not only improves digestion (through fermentation which benefits gut bacteria), but also intestinal motility, relieving constipation and protecting the colon mucosa of the extended exposure to the toxins in feces. At the same time, dietary fiber helps lower bad cholesterol levels by preventing the intestinal absorption of a part of the fats we consume. As a result, eating soybeans contributes to both cardiovascular and digestive health.
4) Exhibit anticancer properties. Soybeans have been found to contain isoflavones (daidzein, genistein, glycitein), a type of antioxidants which both mimic estrogen hormones and exhibit antiestrogenic effects. Such compounds are known as phytoestrogens, or plant estrogens, and have been found to be both beneficial and dangerous for human health.
On the one hand, soybeans and soy products exhibit antiestrogenic effects in the sense that they appear to limit the impact of the endogenous estrogens (produced by our endocrine system), thus protecting us from the damaging effects of too much estrogen. This translates into a lower incidence for hormone-sensitive cancers such as breast cancer due to the beneficial effects phytoestrogens have on the endocrine system. This reduction in the incidence of breast cancer as a result of soy products consumption appears to be more pronounced in Asian populations.
On the other hand, studies reveal that phytoestrogens can actively disrupt hormone balance in both humans and wildlife due to their estrogen-like behavior. In humans, a high intake of phytoestrogenic foods such as soybeans and soy products has been linked to health problems such as infertility, endometriosis, polycystic ovarian syndrome or cancers of the reproductive system as well hormone-sensitive cancers such as breast cancer. What is interesting is that Caucasian women appear to have a higher incidence of breast cancer as a result of soy products consumption.
5) Contain phytic acid. Phytic acid, also found in cereals, grains and some seeds, boasts antioxidant and anti-inflammatory properties. Furthermore, an article published in November 2003 in The Journal of Nutrition reveals that the compound appears to inhibit cancer growth. At the same time, phytic acid binds to dietary minerals such as zinc, calcium or iron, making them harder to absorb and encouraging the onset of nutrient deficiencies. Cooked, fermented soybeans or soy sprouts are estimated to have a considerably lower phytic acid content.
6) Exhibit antifungal properties as a result of the vegetable’s glyceollin content. Glyceollins not only exhibit antifungal properties against Aspergillus sojae, but also boast antiestrogenic properties thanks to which they protect against the harmful effects of endogenous estrogens.
7) Good vitamin and mineral content. Soybeans boast generous amounts of vitamins and minerals, containing good amounts of calcium, iron, magnesium, phosphorus, potassium and zinc as well as good amounts of B vitamins, vitamins K, C and A. Nutritionally speaking, soybeans are nourishing vegetables. However, their high phytic acid content inhibits, to a certain extent, the absorption of dietary minerals, especially if poorly cooked.
So is soy good for us? According to researchers, only a moderate consumption of the legume is beneficial for us (no more than 25 g of a day). An increased intake of soybeans and soy products, especially soybean supplements, can have negative effects in the long run, worsening Irritable Bowel Syndrome, interfering with normal thyroid function (with symptoms such as goiter, constipation, drowsiness), an increased activity exhibited by genes stimulating tumor cells proliferation and even an increase in the incidence of estrogen-sensitive cancers and reproductive system disorders in both females and males.
Despite several proven health claims, it is still unclear how soybeans and soy products affect each individual in particular. Researchers also draw attention on the fact that there are some categories of people that are particularly vulnerable to the side effects of eating soy, so while the legume might be good for some, it might be cause serious health problems to others. Moreover, many people have been found to be allergic to soybeans and soy products. Soy allergy and soy intolerance may cause symptoms such as diarrhea, vomiting, hives or anaphylaxis.
There is also the lingering issue of genetic modification. It is estimated that over 90% of all soy is genetically modified. This means that the plant’s DNA has been altered by means of genetic engineering techniques such as artificial breeding and mutation breeding. Genetic modifications often include the exposure of plants to radiation, chemicals, potential carcinogens, etc. Overall, a growing body of evidence appears to suggest that soybeans and soy products are not as healthy as we are led to believe.